This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-283153, filed Oct. 4, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to an ultrasonic treatment instrument for medical operation in use for treatment of human tissues by ultrasonic vibration energy.
As shown in FIG. 3, a conventional ultrasonic treatment instrument 100, which is used for a medical operation under a microscope, comprises a handpiece 106 having an ultrasonic vibrator for generating the ultrasonic vibration inside a cover, a probe 103 for transmitting the ultrasonic vibration generated by the ultrasonic vibrator, and a sheath 102 for covering the probe 103 from the outside. A distal end of the probe 103 protrudes from a distal end of the sheath 102 and is composed of a treatment portion 101 for treating human tissues by the ultrasonic vibration transmitted by the probe 103.
In the conventional ultrasonic treatment instrument 100, generally, the probe 103 or the handpiece 106 is bent for the purpose of preventing interference to the microscope and maintaining the field of view of the microscope. In FIG. 3, the probe 103 is bent at one portion such that a central axis 02 of the probe 103 is at a predetermined angle to a central axis O1 of the handpiece 106 and that the treatment portion 101 is largely eccentric from an extension of the central axis O1 of the handpiece 106.
Jpn. Pat. Appln. KOKAI Publication No. 8-224252 discloses an ultrasonic treatment instrument for medical operation whose probe 103 is bent at two portions so as to maintain a further wider field of view of the microscope. In this case, one of the two bent portions is positioned near the distal end of the probe. EP 0482847A1 also discloses an ultrasonic treatment instrument for medical operation whose probe 103 is bent at two portions.
Incidentally, a treatment instrument in use under observation of the microscope must be designed such that it is possible to delicately handle the treatment instrument without interfering with the microscope at a handpiece side of the treatment instrument or obstructing the field of view of the microscope. Particularly, in the medical fields such as brain surgery, spinal surgery and the like, the treatment instrument needs to be led to a diseased part through a narrow hole generally called a key hole. For this reason, the treatment instrument used in these fields must be designed such that it is possible to delicately handle the treatment instrument in the key hole without obstructing the field of view of the microscope.
When maintaining the field of view of the microscope and preventing the interference with the microscope are considered only, the treatment instrument only has to have a shape shown in FIG. 3. However, the shape of FIG. 3 is inadequate, in order to delicately handle the treatment instrument as the surgeon expects and, particularly, to allow the treatment instrument to access a diseased part through a narrow hole called a key hole.
That is, the treatment portion 101 of the ultrasonic treatment instrument 100 shown in FIG. 3 is largely eccentric from the extension of the central axis O1 of the handpiece 106. Therefore, it is possible to avoid the interference with the microscope (or other treatment instruments) without obstructing the field of view of the microscope, but difficult to delicately handle the treatment instrument without considering the degree of bending of the probe 103. For example, when the surgeon applies the force along the central axis O1 of the handpiece 106 without considering the degree of bending of the probe 103, he is willing to push the distal end of the probe 103 in the central axis O1. In fact, however, as the direction in which the surgeon applies the force almost unconsciously is not equal to the moving direction of the treatment portion 101 at the distal end of the probe 103 due to the above-explained eccentricity of the treatment portion 101, the distal end of the probe 103 moves in a direction which the surgeon does not expect. This gives very strange feeling to the surgeon and prevents him from delicately handling the treatment instrument.
Similarly to a case where writing a small and beautiful character with a bent writing instrument is not easy, it is difficult to delicately handle the conventional ultrasonic treatment instrument shown in FIG. 3 without considering the degree of bending of the probe 103 thereof. In addition, as various treatment instruments are utilized for the respective purposes in a long-time operation, the surgeon must have a big burden in using the ultrasonic treatment instruments while considering the degree of bending.
As for the ultrasonic treatment instruments disclosed in Jpn. Pat. Appln. KOKAI Publication No. 8-224252 and EP 0482847A1, the same problem as the above-described one occurs as the treatment portion 101 is largely eccentric from the extension of the central axis 01 of the handpiece 106. Particularly, in the treatment instrument of Jpn. Pat. Appln. KOKAI Publication No. 8-224252, one of two bent portions is positioned in the vicinity of the distal end of the probe, i.e. the vicinity of the treatment portion is bent. Therefore, it is inconvenient to handle the treatment instrument in the narrow key hole and the treatment instrument may interfere with other treatment instruments that are simultaneously used. The treatment instrument of EP 0482847A1 also has two bent portions as the distal end of the probe and, therefore, insertion into the key hole is substantially impossible and the treatment instrument cannot be used under a microscope.
The object of the present invention is to provide an ultrasonic treatment instrument for medical operation which, even when used together with a microscope, does not obstruct the field of view of the microscope, and which can prevent interference with the microscope or other treatment instruments and can be delicately handled without causing an uncomfortable feeling.
The object of the present invention can be achieved by an ultrasonic treatment instrument described below. That is, an ultrasonic treatment instrument for medical operation according to the present invention comprises a handpiece having a cover serving as a grip, and an ultrasonic vibrator provided inside the cover for generating ultrasonic vibration, a vibration transmitting member connected to the ultrasonic vibrator while extending from the handpiece, for transmitting the ultrasonic vibration generated by the ultrasonic vibrator, and a treatment portion provided at a distal end of the vibration transmitting member, for treating living body tissues by the ultrasonic vibration transmitted by the vibration transmitting member. The vibration transmitting member extends while bent at a plurality of bent portions so that the treatment portion is positioned on or near an extension of a central axis of the handpiece.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.